1. cytoskeleton of the cell BY Nouf al-yami

2. cytoskeleton of the cell The cytoskeleton forms the skeleton of each cell and is responsible for its specific shape.

3. It consists of several classes of structural element which are: the Microtubules the Microfilaments. the Intermediate filaments.

4. the Microtubules in all kinds of cells. cylindrical filamentous structures 25 nm. made of protein tubulin. appear as tiny circles in cross section. anchored in region near the centeriole of the cell. long and are elastic to bend without breaking.

5. Figure: Falgilam.

6. function of Microtubules Skeleton of the cell. Transport. Move the cilia through the action of Axonemal Dynein. Cell division(cytotoxic drugs).

7. the microtubules

8. the Microfilaments There are tow type(7nm) of microfilaments: 1- Actin filaments (thin filament, muscle cells). 2- Myosin filaments (thick filaments, muscle cells).

9. function of Microfilaments Muscle contraction. Amoeboid movemement (white blood cells). Blood clot( blood platelets). The separation of the dividing cells. Microvilli (terminal webs).

10. The Microfilaments

11. the Intermediate filaments There are five types (10nm): keratin filaments (epithelial cells). Desmin filaments (smooth muscle,skelent,cardic). Vimentin filaments (connective tissue fibroblast cells). Neuro- filaments (nerve cells). Glial filaments (neuroglia cells).

12. the Intermediate filaments

14. Microvilli They are finger like projection on the surface of certain cells of the body, for example; cells of the intestine. They are formed of microfilaments covered with the cell membrane. They are increase the surface area of the cell.

15. Microvill